Radiation exposure of the staff of nuclear power plants of the German Democratic Republic

In the German Democratic Republic (GDR), the first nuclear power plant was put into operation at Rheinsberg in 1966, providing 70 MW of electrical power. It was followed by another three reactors installed at Greifswald in 1973, 1974 and 1976, respectively, with a power output of 440 MW(e) each. All reactors are under the charge of the VEB Kernkraftwerk Bruno Leuschner, Greifswald. The normalized collective dose equivalent from external irradiation, i.e. the cumulative collective dose equivalent divided by the total electrical energy produced, is about 5 man.rem/MW(e).a for the Rheinsberg plant and 0.66 man.rem/MW(e).a for the Greifswald plant. The normalized collective dose equivalent due to the nuclear energy programme of the GDR amounts to about 1.3 man.rem/MW(e).a. The average contribution of the internal radiation exposure to the whole-body exposure is less than 1%, after converting internal dose equivalents into effective dose equivalents. Decontamination of the primary circuit and shielding measures were applied to reduce radiation exposure during inspection and maintenance. The factors of dose-rate reduction achieved lie in the range of from 3 to 15 for inspections and from about 5 to 30,000 during maintenance. An attenuation factor of 30,000 was attained when a heavily shielded cabin was used for the inspection of the inner surface of a reactor pressure vessel. (author)